Apparatus for supplying air under pressure



Jan. 3, 1928.

J. C. .WOODFORD APPARATUS FOR SUPPLYING AIR UNDER PRESSURE Filed Jan.I925 Patented Jan. 3, 19 28.

UNITED STATES OSKAIDOSA, IOWA, ABBIGNOB Oil ONE-HAL! Tb VIBGII: D.

cos c. woonronn, or

BARKER, 01 OAK PARK, ILLINOIS.

APPARATUS FOR BUPPLYING AIR UNDER rnzssm My invention relates toapparatus for cupplying air under pressure from sources which containair under higher ressure than that which is tov be receive in the Ispaces to be supplied. My invention 18 of particular service inconnection w th apparatus that is employed for supplying pneumatic wheeltires with air. By means of my invention the apparatus may be set tosupply the requisite amount of air, and after havm g supplied therequisite amount of air the source of air under higher pressure w1ll beautomatically disconnected. With prlor equipment it is necessary tofrequently test 5 the ressure of the air that has been supplie aproceeding which is rendered unnecessary by means of my inventlon.

In practicing my invent on piping 1s employed through which air 1sconveyed from 20 its source. there being a valve between the source andthe piping, this valve being constrained to move in a closing dlrection.Mechanism is employed that enables or permits the valve to close, thismechanism bein so connected with the piping and of suc construction asto be controlled by the pressure of the air conveyed by the piping, thethe air upon.

mechanism being operable by attaining sufiicient pressure, to enable theclosure of the valve. Thus, when the apparatus is used for fillingpneumatlc tires, the valve which was opened by suitable means for thepurpose of supplymg air to such a tire; is enabled to close when thepressure of the air flowing in the piping has reach a predeterminedamount. The mechanism that enables the closure of the valve alsodesirably takes part in opening the valve, this mechanism beingpreferably constrained to operate reversely upon sufficient reduction ofthe air pressure to effect, or take part n effecting, the opening adustment of the valve.

In the preferred embodlment of the 1nvention said valve is provided witha spring which is enabled to close the valve when the pressure of theair passed to the piping has reached a redetermined value, a resultwhich arlses w th the 8.l d of the valve controlling mechanismdescribed. In the preferred embodiment of the invention the valvecontrolling mechan sm 13 located in a chamber into which air sdischarged from the piping, there being n th s chamber an operatingelement which 1s Application fled January 21, 1985. Serial 80. S

by the valve REISSU ED moved in one direction by the air admitted to thechamber when the air attains suflicient pressure, and which isconstrained to move in the reverse direction when the air pressure hasbeen sufliciently reduced. The aforesaid operating element is incontrolling relation to, or is enabled to take partin controlling themechanism that is adapted to open the valve, and performs this functionwhen the pressure of the air-is sufliciently reduced to permit theoperating element of this mechanism to act of itself to secure thisresult. When the pressure of the air being supplied has reached apredetermined value the operatin element is reversely operated torelieve t e valve of its opening influence and permit it to be closed byits spring. In the preferred embodiment of the invention a ma et isemployed in direct opening relatlon to the valve, the circuit of thismagnet ,bein gov-' erned by a relay, the circuit of the re ay, in turn,being governed by a switch which includes a movable contactarm which isthe preferred form of the aforesaid operating member located within theaforesaid chamber. This switch arm is constrained to engage its contact,when the pressure within the chamber is sufiiciently reduced, toenergize the relay, the circuit of the valve opening magnet being closedby the armature switch of the relay each time the relay is energized.When the pressure of the air within the chamber reaches a predeterminedvalue it operates upon a diaphragm which then moves to place theaforesaid switch arm in an open circuit adjustment to de-energize therelay and the magnet controlled by the relay, whereupon the valve ispermitted to close. The point at which the diaphragm may thus respond tothe pressure of the air received in the chamber may be regulated by ahandle or; knob controlled spring, so 4 that the-apparatus will notcease to function until air under the particular pressure dc slred issupplied to the tire or other space that is to be furnished therewith.

-In the. preferred embodiment of the invention the piping is providedwith a second valve which is an outlet valve, this second valve beingmanually opened each time air is to be supplied and being manuallyclosed when air under the desired pressure has been supplied in orderthat the air may be trapped within this chamber, at this pressure, tomaintain the valve controlling mempiping 2, this valve 19 is normallyclosed to her in the chamber in the adjustment wherein the first valvemay remain closed. However, the outlet valve may be omitted to permit anadjustment of the member within the chamber that would cause the, othervalve to open were it not for a device that is then employed forrendering this member ino erative. In the case of the electro-magwhocontrol of thesup ly valve in a systemlacking the outlet va e, amanually controlled sw1tch may be employed in the circuit of the relayfor the purpose stated.

The invention will beinore fully explained in connection with theaccompanying drawing which is a diagrammatic illustration of thepreferred embodiment thereof as constructed and arranged for fillingpneumatic tires.

The tank 1 contains air under pressure that is much higher than thatwhich is to be supplied to pneumatic tires. Air may be supplied fromthis tank by way of piping 2. The air passes from the tank into thevalve chamber 3 which is connected at its inlet end to the tank and atits outlet end with said piping. A valve 4 is located within the valvechamber and is pressed upon by a spring 5 in a closing direction, saidvalve bein constrained by the spring to adjust itsel in closed positionwhen no air is to be supplied. The valve chamber is inclusive of anenlargement 6 thereof into which the valve stem 7 projects. This-valvestem is square or polygonal'in contour while the passage in the wall 8that separates the two parts of the valve chamber and through which thevalve stem operates, is circular, so that when the valve is unseated airmay flow to the piping. An electro-magnet 9 is provided for opening thevalve, the armature of the magnet carrying an operating arm 10 which isfixed upon the armature shaft 11 that passes into the valve chamberportion 6 through air tight bearings. When the magnet is energized thearm 10 is turned to move the valve stem 7 and the valve 4 inwardlyagainst the force of the spring 5 to permit air to flow through thepiping. The circuit of the magnet includes the armature switch 12 of arelay 13. The relay circuit includes a controlling switch that isinclusive of an operating switch contact arm 14 and a contact member 15,complemental to this arm. The switch members 14 and 15 are locatedwithin an air chamber 16, there being suitable air tight circuitconnections 17, 18, extending through the chamber and including theswitch members in circuit with the relay winding. When the valve 4 is tobe opened the relay 13 is energized to energize the mag net 9 whosearmature thereupon opens the valve. If the piping is supplied with anoutlet valve, such as that indicated at 19 in connection with the pipe20 branching from the trap air under pressure within the chamber 16 tohold the switch arm 14 away from the contact 15 when the apparatus isnot in use, a result which is secured with the aid of a diaphragm 21which is subject to the pressure of the air in said chamber and whichthen moves the switch arm 14 from. its contact 15 through theintermediation of the abutment screw 22 that presses upon the switch arm.14 for this purpose, this abutnicnt screw being carried upon a bracket22' that is provided upon the diaphragm. When air is to be supplied tothe tire, indicated at 23, the branch pipe 20 is first connected withthe tire nipple whereafter the valve 19 is opened. When this valve isopened the pressure in the chamber 16 is reduced to permit the spring 24to move the diaphragm 21 in a direction to move the abutment 22 out ofactuating engagement with the switch arm 14. W'hen the abutment 22 isthus withdrawn from the switch arm 14 this switch arm engages itscontact 15, the switch arm being constrained to move in a switch closingdirection by reason of its own resilience. When the switch 14. 15 isclosed, the circuit of the relay 13 is closed. When the relay isenergized its armature switch 12 is closed to close circuit through thevalve opening magnet 9. The relay winding is shown as being in bridge ofthe supply mains 25 extending from. the generator 26, the switch 14, 15being in series with the relay winding and in the same bridge therewith.The armature switch 12 of the relay is serially included with thewinding of the magnet 9 and in another bridge therewith between themains 25. The magnet portion of the relay is in the form of a solenoidhaving an iron core 27 which is thrust outwardly by a spring 28 when therelay is de-energized and against the force of which spring said core ismoved when the relav is energized. The iron core of the relay carries abrass rod 29 that is in electrical connection therewith. This brass rodcarries metallic flanges or e11- largements 30, 31, that are inelectrical connection therewith. and also carries two collars ofinsulation 32. 33, between which the portion 30 is disposed. The brassrod 29 and the parts 30, 31, 32, and 33, carried thereon, are disposedbetween the brushes 3.4 of one pair, and the brushes of another lthiwhich the core 27 has sliding electrical contact, the metallic ring 13the switch arm 12 then in electric connection with the ring, the windingof the magnet 9, the lower main 25 to the lower brush of the generator26. When the relay is energized it opens the valve 4 as previouslydescribed, whereupon air finds passage through the piping 2, the branchpipe 20, to the tire 23 by way of the opened outlet valve 19, the switcharm 14 having engaged its contact 15 when the valve 19 was initiallyopened, to enable the magnet 9 to open the valve, as described. When theair fiows through the pipe 2 it is not only received in the tire 23 butis also supplied to the chamber 16 to cause the movement of thediaphragm 21 to the left, whereupon the abutment 22 is pushed againstthe switch arm 14 to separate this switch arm from the contact 15 toopen the relay circuit. The spring 28 is then effective to depress thecore 27. When this core is fully depressed the metallic enlargement 31is disengaged from the brushes 35 to open circuit of the magnet 9 whichincludes the left hand one of these brushes. As the relay 13 isinstantly deenergized upon opening of the valve 4, I provide means forretarding the release of the solenoid core 27 to delay opening of thecircuit of the magnet. As illustrated, this retarding means includes anapertured plate 36, a valve disk 37 pressed against this plate by aspring 38 to close the apertures therein, an abutment 39 upon the rod 29against which the bottom end of the spring 38 is engaged, and a chamber40 surrounding the rod 29 and its enlargement 31 and enclosing the parts36, 37, 38 and 39. This chamber 40 contains oil 41 which seeps slowlyaround the plate 36 when the spring 28 lowers the solenoid core. Thedelay effected in the movement of the metallic element 31 out ofengagement with the left hand brush 35 is sufficient to permit anappreciable amount of air to be passed to the tire. When the enlargement31 becomes separated from the left hand brush 35 the magnet 9 isde-ener'gized to permit the spring 5 to close the valve 4. If sufiicientair has not been supplied to the tire the pressure of the air within thechamber 16 again becomes reduced to permit the spring 24 to move theabutment 22 away from the switch arm 14, whereupon this switch arm againengages its contact 15 to again energize relay'13 with the resultsbefore described. These operations are repeated until suflicient air isaccumulated within the tire whereupon the diaphragm. 21 is again andfinally pressed to the left by the air that is then under suflicientpressure to maintain the diaphragm in this position when the outletvalve 19 is closed, an adjustment which is effected before thebranch-pipe 20 is disconnected from the tire. The switch 14, 15, remainsopened to permit the spring 5 to maintain the valve 4 closed until thebranch pipe 20 is connected with another tire requiring rcfilling,whereupon the pressure of the air in the chamber 16 is again reduced byopening the outlet valve 19 to permit the spring 24 to move thediaphragm 21 to the left to release the switch arm 14 and permit it toengage the contact 15 as and with the results hitherto set forth. Thepressure at which the diaphragm is to be operated by the air in a mannerto maintain the switch 14, 15, opened, is regulable by the knob orhandle 42 whose hub 43 is screwed into the tubular extension 44 of thechamber 16. This handle isprovided with an index 45 that may be placedin registry with scale marks provided upon the index bracket 45' andwhich marks indicate the various pressures to which the apparatus may beadjusted.

The lamp 46 is in bridge with the mains 25, both brushes 35 being in thesame bridge with the lamp. When the relay is energized the brushes 35are connected by the element 31 to light the lamp, and when the relay isde-energized and its core 27 is fully depressed the lamp 46 isextinguished. The lamp will thus intermittently glow during the tirefilling process and will cease to glow when the tire is filled. Anaudible signal such as the bell 47 may also be employed, this bellincluding an operating electromagnet which is in circuit with thebrushes 34 that are connected by the element 30 when the relay isenergized to cause the bell to sound when air is being supplied, thebell ceasing to operate when the valve 4 is closed, the bell thusaccomplishing audibly what the lamp 46 accomplishes visually. If thegenerator 26 furnishes alternating current a step-down transformer 48 isdesirably interposed between the mains 25 and the bell 47.

If the outlet valve 19 for the piping 2 or the branch pipe 20 isomitted. the pressure in the chamber 16 is not maintained when the valve4 is closed, the switch 14, 15 being closed when the valve 4 is closed.To prevent the switch, when normally or idly closed, from energizing therelay 13, I employ a switch 49 in series with the switch 14, '15, thisswitch 49 being opened when the switch'14. 15 is idly closed and beingclosed when the apparatus is being employed for its purpose. Either ofthe elements 19, 49 serves to start the apparatus into operation, theelement 19 functioning when it is opened to permit the passage of airfrom the piping, and the element 49 functioning when it is closed toconnect the relay in circuit.

I claim In a device for charging a receiver with compr ssed air, thecombination of a source of com ressed air, adjustable means for limitinthe ultimate pressure to which said receiver is to be charged, a conduitconnecting the source of compressed air with the receiver, a valve insaid conduit, means tending to close said valve, means opening saidvalve when the pressure in the conduit falls to that at which the deviceis adjusted, and

means timin the open interval of said valve, 10 whereby In witnesswhereof, I hereunto subscribe 15 my name.

JOE C. WOODFORD.

